The prior art is documented with examples of spinal support plates and the like. In a most common example, a titanium plate is utilized and which his attached, such as by bone screws, to succeeding vertebral locations in order to fuse, or immobilize, a given area of the spine. Shortcomings associated with the installation of such fixed plates include both the pain and discomfort of implantation, along with the subsequent loss of flexibility.
A further problem associated with a lateral misalignment condition existing between the vertebrae is pinching of the lateral nerve branches of the spinal column. This problem is particularly severe in respects to the seating arrangement established between the (inwardly facing) superior articular process facets and above-succeeding and overlapping (outwardly facing) inferior articular process facets of the inter-lumbar vertebrae (L1-L5).
Among the prior art is U.S. Pat. No. 5,571,191, to Fitz, which teaches an artificial facet joint incorporating both of a conical or pyramidal shaped superior component which is fastened to and over a distal tip of an inferior articular process. A corresponding inferior component further mounts over the superior articular process and exhibits a configured low-friction surface for abutting the superior component.